Core for concrete forms



Aug.' io 1926.v v

5F. H. FRANsQN CORE FOR CONCRETE v FORMS Filed March 9. 192e Patented ng. 10, 1926.

tlikii' Sithu FTFJNT QFFiCE.

con-E Forv CONCRETE nomas.

Application filed March 9, 1.926. Serial No.

This invention relates to a collapsible form which could be employed for a multitude of ases, such as a core for casting hollow building wails; or, in the manufacture of paper or textiles, it could be used as a form or inandrel upon which to wrap the materialand for any other use desiring a form which can be collapsed andremoved from the formed material. l

The principal object of the invention is to provide a device of this character which can be readily contracted and yetwhich, when expanded, will withstand great pressure without collapsing.

Another object of the invention is to so construct the device that two or more of the forms may be inter-connected so as to act simultaneously, thus allowing it to be eX- tended to any desired length.

A further object is to provide a form of this character which can be readily disassembled, without the use of tools, so as to occupy but a minimum of space when being shipped or transported.

A still further ob ect 1 is to provide means for extending the forms laterally as well as longitudinally by introducing co-acting sectional parts.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and eiiiciency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

1n the drawing:

Fig. 1 is a perspective View of my 1mproved form.

Fig. 2 is a side elevation of two of the forms interconnected.

Fig. 3 is a plan view of the form, illustrating in solid line the collapsed position, and in broken line, the extended position.

Fig. t is a detail view illustrating the manner in which several of the forms'may be nested together for packing purposes.

Fig. 5 is an enlarged plan view of the inter-locking member.

rPhe form comprises two U-shaped sections of sheet metal 10 and 11, joined together by hinges 2G and hinge ins 12 and 13. The

hinge pins 12 and 13 a so secure a collapsible of hinge pins 19 and 20. The key member lcoinprises a sheet metal 'strip 21, the longitudinal edges of which are rolled atr 25 to form the hinges foi1 the hinge pins 19 and 20. j Secured to opposite sides of the strip 21 are stiffening bars 22 and 23, which increase the torsional strength of the key member 18.

Let us assume the form is in the position of Fig. 1, that is, extended. Should it be del sired to contract the form to a smaller cross section so as to remove it vfrom a surrounding substance, the key member 18 is turned, by means of a wrench or other suitable tool, in a clock-wise direction (looking downward). rEhe rotating key member draws the cross braces 111 and 15 and the hinge pins 12 and 13 inwardly, thus reducing the width of the form at its center and drawing the entire form inwardly, as indicated in Fig. 3.

This allows it to be readily withdrawn from a surrounding substance.

Then in the extended position of Fig. 1, the Vfeet 16 and 17 rest against the stiffener bars 22 and 23 of the keyV member 18, thus effectively preventing the form from collapsing from external pressure.

Shoul l it be desired to increase the length of the form, two or more of the single forms of Fig. 1, may be joined together, as indicated in Fig. 2, by inserting longer hinge pins for the pins 12, 13, 19 and 20, that will pass entirely through the hinges of all the connecting forms. Should it be desired to increase the width of the form of Fig. 1, eX- tension plates 27 may be inserted between the edges of the U-shaped sections 10 and 11, as indicated in Fig. 2, and joined to these sections by means of the hinge pins 12 and 13. The forms may be still further extended by inserting additional extension plates and joining them together by the hinge pins. Uien extending the forms laterally, collapsible cross braces are employed at each of the j oining points of the various sections.

While a specific form of the improvement has been described and illustrated herein, it

is desired to be understood that the. same may be varied, Within the scope of the appended Claims, Without departingl from the spirit of the invention.

Having thus described the invention7 what I claim and desire secured by Letters Patent is l. eontractible form Comprising two Sheet metal sections, U-shaped in cross section; pins hingedly joiningl said sections at their open extremities; a collapsible Crees brace closing' the open sides o? sai-d said Collapsible cross brace comprising' two seetions hinged to said pins and projecting inwardly therefrom; and a third section hinged to said two sections 2. A eontraetible form comprising; two s-.ieet metal sections, lol-shaped in cross seetion; pins hingedly joining said sections at their open extremities; a collapsible cross brace closing,- the open sides et said U, said collapsible cross brace comprising two seetions hinged to said pins and projecting inwardly therefrom; and a third section hinged to said two sections, said third seetion having fia-t surfaces arranged to Veooperate with flat surfaces on said two seetions to prevent the structure from collapsing until said third section is rotated.

3. A contraotible form Comprising two sheet metal sections, Ed-shajoed in Cross seotion; ins hingedly joining' said sections at their open extremities; and e Collapsible cross brace closingV the open sides ot said U, said eontractible cross brace extending throughout the length of said Sections and eomgrising three members arranged to maintain alignment With each other until one of said members is rotated.

Qn testimony whereof, I ahx my signature.

FRITZ HUGO Hermsen.Y 

